Siloxanes useful in permanent waving of hair

ABSTRACT

The use of siloxanes for conditioning of hair is disclosed. They hold particular usefulness as substitutes for oxidizing agents in the hair waving process. A novel polymeric composition which comprises a silanol endblocked polydiorganosiloxane, cyclic siloxanes, a chlorobenzyl-functional siloxane and a catalyst is also disclosed.

This invention pertains to siloxanes that are useful as conditioningagents in permanent waving of hair. The siloxanes of this invention maybe applied in place of the peroxide rinse in the typical permingprocess.

BACKGROUND OF THE INVENTION

Hair is comprised of structural proteins known as keratin. In theprocess of permanent waving of hair, keratin disulfide (KSSK) bonds arebroken by the addition of a reducing agent to the hair. The hair is thencurled and a oxidizing agent rinse is used to form new cross-linked(curled) KSSK bonds. Thioglycolates are the typical reducing agent usedin the art which break the KSSK bonds and allow the formation of thiolgroups (KSH) on the hair strands upon the addition of water. HydrogenPeroxide is the typical oxidizing agent used in the restoration of thekeratin disulfide bonds. It is usually desirable to apply thesecompounds to the hair from aqueous or occasionally a solvent media.

The use of peroxides in the perming process can result in damaged hairor remove non-natural color from hair. The peroxides used in perming aregenerally used to impart the following reaction with the hair.

    2K--S--H+H.sub.2 O.sub.2 →K--S--S--K+2H.sub.2 O     (I)

However if two K--S--H groups are not present for the reaction, (I), totake place it is theorized that the following reaction takes place whichresults in damaged hair. ##STR1##

The use of certain silicones in the perming process are known in theart. For example, U.S. Pat. No. 4,331,167 to Wajaroff teaches acomposition that is applied to the hair prior to the perming processwhich comprises a methylpolysiloxane, a paraffin or isoparaffin, atleast one cation active, non-capillary active compound and at least oneampholytic, capillary active imidazoline compound. This composition,when applied, allows for the retention of natural luster and oils aswell as easing the process of combing, dividing and winding the haironto the permanent wave rollers.

U.S. Pat. No. 3,687,606 to Simmler et al. teaches the use ofepoxy-organo-silanes in the hair perming process. These silanes areapplied after the hair has been curled, the reducing agent applied andthereafter rinsed with water but, prior to the application of theoxidizing agent. The use of the epoxy-organo-silanes during the permingprocess allows for better retention of curl in the hair. The problemwith this method is that the perming process now requires threetreatment steps which greatly lengthens the time to complete the permingprocess and the epoxy-organo-silanes are not water soluble.

U.S. Pat. No. 4,770,873 to Wolfram et al. teaches a neutralizingcomposition for hair waving and straightening comprised of a typicalneutralizing (oxidizing) agent and an additive consisting of a siliconepolymer (preferably in an emulsified state). The use of the siliconeadditive in the neutralizing (oxidizing) compound imparts durableconditioning benefits to the hair as well as reducing the waterretention of the hair.

U.S. Pat. No. 4,798,722 to Edman et al. teaches a reducing solutioncontaining additives comprised of a strong hydrogen bonding amino acidsand a water soluble or emulsifiable silicone-based compound.Improvements in curl retention, manageability, feel and appearance areprovided by a synergistic effect of the amino acid and the silicone.

Prior art lacks the teaching of silicone compounds that are useddirectly in place of the reducing or oxidizing agents. The improvementsimparted by known silicones are brought about by applying them asadditives blended into the reducing or oxidizing agents or by applyingthem independently as additional steps in the perming process.

There is also a lack of teaching of silicone compounds that are bondeddirectly into the hair structure. Perming processes known in the artteach methods in which the hair is oxidized back into its naturalkeratin disulfide (KSSK) bonds.

The novelty of this invention arises from the use of silicone compoundsthat are applied in place of the peroxide (oxidizing) solution. This,thereby, allows the incorporation of silicone into the hair structure.

Several chlorobenzyl functional siloxanes and methods for theirpreparation are known in the art. For example U.S. Pat. No. 3,925,434 toChuang teaches an improved method for making chlorobenzyl functionalchlorosilanes via the reaction of vinylbenzyl chloride with achlorosilane.

Also, U.S. Pat. No. 3,413,329 to Pepe et al. teaches chloromethylatedaralkyl silanes, alkoxysilanes and siloxanes that are useful inapplications including lubricants, hydraulic fluids, coating resins formetals and fibers, and elastomers. Applications for use in hairtreatment is not disclosed.

It is an object of this invention to show the use of siloxanes in theperming process.

It is also an object of this invention to show the added benefitsobtained from using a siloxane in place of the peroxide rinse in thehair perming process.

THE INVENTION

This invention pertains to the use of siloxanes which containelectrophilic functionality, in particular those that contain thechlorobenzyl group, that are used in place of peroxides in the hairperming process. Siloxanes applicable in this invention are selectedfrom the group consisting of the general formulas ##STR2## wherein R¹ isindependently selected from alkylene groups containing 1 to 10 carbonatoms, arylene groups containing 6 to 10 carbon atoms, and alkarylenegroups containing 6 to 15 carbon atoms; any of said groups optionallycontaining an ether oxygen within the aliphatic segments thereof; Y isselected from functionality providing an electrophilic center; R² isindependently selected from an alkyl group containing 1 to 6 carbonatoms and an aryl group containing 6 to 10 carbon atoms; R³ isindependently selected from the group R² and the groups --O--R² and --R¹--Y where R¹, R² and Y are as defined above; and x has the value of 1 to5.

R¹ is further exemplified by ethylene, propylene, isobutylene,phenylene, ethylphenylene, glycidoxy, and others. R² is furtherexemplified by methyl, ethyl, phenyl, and others. Y is furtherexemplified by groups such as halobenzyl, epoxy, and others withchlorobenzyl being the preferred functionality. When x is 1 or greaterit is preferable that at least one R³ group be represented by --R¹ --Yand the remainder of said R³ groups be selected from R².

The siloxanes useful in this invention are further exemplified by thosethat possess electrophilic functionality, have a low molecular weightand are compatible with aqueous or solvent delivery systems. Compoundscontaining at least electrophilic bifunctionality are preferred.However, compounds initially present in the perming solution may onlycontain mono-functionality and may react prior to or during theapplication process to produce at least bi-functionality.

The need for the low molecular weight is necessary for the molecule tobe able to diffuse in and out of hair at a reasonable rate. Molecularweights of less than 800 and more preferably less than 400 areapplicable to achieve sufficient diffusion in conventional aqueous haircare systems.

The compounds of this invention must be compatible with aqueous orsolvent delivery systems so that the silicones can be easily and evenlyapplied to the hair after it has been wound on the curling rods. This isnot a requirement of the materials and can be avoided if the compoundscan be blended with low viscosity fluids that allow saturation of thechlorobenzyl compounds into the hair. Solvent and aqueous deliverysystems are preferred because of cost and ease of handling.

The process for applying these materials consists of following normalperming procedures. The hair is washed and set on permanent wavingcurlers. The thioglycolate reducing solution or lotion is applied. Thehair is allowed to set until the desired curl is achieved at which timeexcess thioglycolate solution is water washed from the hair. Thesiloxane is applied from a solution and allowed to set for a briefperiod of time. The hair is then water washed and styling completed asdesired.

It is believed that the following reaction occurs on the hair structureduring the neutralization process using, for example, achlorobenzyl-functional siloxane ##STR3## where R¹ is as describedabove. This allows the incorporation of the silicone into the structureof the hair providing more durable conditioning effect. It is alsobelieved that the K--S--C-- bond provided by the materials of thisinvention are stronger than the K--S--S-- bonds provided in typicalperms thereby leading to longer lasting effects of the perm (permanentconditioning).

The siloxane neutralizer can be applied in the form of solvent or othersolutions. Depending on the nature of the compound (i.e. monomeric,polymeric, number and type of functional groups etc.) will determine theproper system for delivery. Polar solvents, in particular acetone andabsolute ethanol, have been found effective for compounds of the formula(III). For compounds of the formula (IV) application can be achieved bythe use of non-polar solvents, silicone delivery systems, propellants,low molecular weight alkanes, isoparaffins and others. The siloxanesuseful in this invention do not appear to be readily soluble in water.It may, however, be feasible to produce emulsions from the materials ofthe formula (III).

When applying the siloxanes of this invention from a solvent system itis desirable to add the siloxane to the solvent such that the siloxanecomprises 0.1 to 50 percent (weight) of the total solution.

It is preferable that the compositions of this invention be applied froma weakly basic solution (pH approximately 8 to 9) or that the hair canbe briefly treated with a weakly basic solution prior to the applicationof the siloxane solutions. Basic materials such as triethanolamine areuseful for direct application to the hair or for addition into thesiloxane solutions. The basic materials are blended into the siloxanesolutions in quantities sufficient to produce the desired pH. If thebasic material is applied directly to the hair, prior to the applicationof the chlorobenzyl solutions, it should be applied from aqueous orsolvent media at concentrations sufficient to produce the desired pH.

Additional materials that are inert to the siloxanes and soluble in thechosen delivery media may be added into the oxidizing solution. Thesecompounds may include active ingredients that impart other desirablecharacteristics into the hair or inactive compounds such a perfumes thatimprove the aesthetics of the solution.

A novel polymeric composition of this invention which has also beenfound useful as an oxidizing and conditioning agent for hair comprisesthe reaction product of a silanol endblocked polydiorganosiloxane fluid,a chlorobenzyl functional silane, low molecular weight cyclic siloxanesand a catalyst.

The silanol endblocked fluids useful in this invention may be furtherexemplified by the general formula ##STR4## wherein R⁴ is independentlyselected from an alkyl group consisting of 1 to 6 carbon atoms and anaryl group consisting on 6 to 10 carbon atoms; and y has the value of 1to 10,000. The preferable silanol fluids of this invention are when R⁴is methyl and y has the value of 10 to 1,000. The silanol fluidsapplicable in this invention are commercially available or can beprepared from known methods.

The chlorobenzyl functional silanes may be further exemplified by thoseof formula (IV) and where at least two of the R³ groups is representedby the alkoxy group (--O--R²), preferably methoxy. When only two of theR³ groups are represented by an alkoxy group it is preferable that theremaining R³ be chosen from R². The compoundchlorobenzylethyltrimethoxysilane is the preferred compound.

The cyclic siloxanes useful in this composition can be furtherexemplified by the general formula ##STR5## wherein R⁴ is as describedabove and z has the value of 1 to 4. Mixtures of cyclics containingvarying z values are also useful in this invention. The cyclic siloxanesuseful in this invention are commercially available or can be preparedfrom known methods.

The catalysts useful may be further exemplified by those catalysts whichare capable of cross-linking a mixture of the above mentionedcomponents. Resulting from catalysis of the cross-linking reaction arethe novel polymer compositions. Organotin or orgaontitanium catalystswhich contain alkyl, aryl or alkoxy groups on the tin/titanium are thepreferred catalysts. The most preferred catalysts are tetrabutyltitanate or dibutyltindilaurate. Catalysts which are known for producingRTV silicone rubbers or elastomers may also be useful in this invention.

The novel polymeric composition is prepared by combining, and therebyreacting, the components described above. It is sometime preferable toblend several of the components together prior to adding in thecatalyst. One such method is to combine the silanol endblocked fluid andsome of the cyclic siloxanes as one solution and the chlorobenzylfunctional siloxane, the catalyst and remaining cyclics as another. Thereaction is initiated at room temperature and pressure when the twosolutions are combined and continues during the use.

It is desirable that the reaction mixture be comprised of 2 to 40 weightpercent of the silanol endblocked fluid, 0.1 to 20 weight percent of thechlorobenzyl functional siloxane, and 0.01 to 5 weight percent of thecatalyst. The remainder of the solution should comprise the cyclicsiloxanes.

When the components are combined in the presence of the catalyst areaction takes place that produces a novel polymeric composition thathas a combination of di-, tri- and tetra-functional silanes andtin/titanium as well as --OH and alkoxy endblock groups.

The chlorobenzyl functionality is also present which can then be reactedwith the hair in the same manner as the other siloxanes (formulas (III)and (IV)) discussed previously in this application. For hair applicationpurposes it is preferable to dilute the polymeric composition inadditional cyclic siloxanes or other suitable solvent systems such thatthe polymer comprises 0.1 to 50 percent (weight) of the solution.

The advantages obtained from using the compounds of this invention asneutralizers in the perming process include a durable permanentconditioning effect, softness of feel and a longer lasting wave due tothe more durable chemical crosslink produced. Also, because of thebonding in the hair structure provided by the silicone, there is lesspotential for reversion of the bonds to free mercaptan thereby providinglower odor.

Because no peroxides are used in the process, hair that has been dyed orcolored can be permed without loss or change to that color or the haircan be permed and colored simultaneously. Perming without peroxides alsoproduces a bona-fide low damage perm.

Also, because of the bonding in the hair structure provided by thesilicone, there is less potential for reversion of the bonds to freemercaptan thereby providing lower odor.

So that those skilled in the art can understand and appreciate theinvention taught herein, the following examples are presented, it beingunderstood that these examples should not be used to limit the scope ofthis invention over the limitation found in the claims attached hereto.

EXAMPLE 1

Four (A, B, C, and D), 2 gram, European Brown, tresses of virgin humanhair were moistened with water, wound onto standard perming rods andtreated with 10 grams of an ammonium thioglycolate acid solution(pH=10). After 30 minutes the hair was rinsed while still in the rodsand blotted to remove excess moisture. The following procedures wereaccomplished for each tress:

Tress A was saturated using a 2.2 percent hydrogen peroxide solution andheld for 5 minutes.

Tress B was saturated for with a basic acetone rinse (pH=9) consistingof 70.1 gram acetone and 4.0 grams of triethanolamine (TEA) and allowedto stand for approximately 1 minute. The tress was then saturated with20 grams of a 5% solution of ##STR6## in acetone and held for 5 minutes.

Tress C was saturated with a solution (pH=9-10) consisting of 23.23grams ethanol, 1.02 grams TEA and 1.25 grams of (VIII) and held for 5minutes.

Tress D was saturated with solution similar to that used in C except1.25 grams of vinylbenzyl chloride was used in place of (VIII). Thesolution was allowed to stand on the hair for 5 minutes.

Upon completion of the oxidation step, all of the tresses were removedfrom the rods, thoroughly rinsed with water, and hung to air dry for atleast 24 hours. The curl produced on tresses A, B, and C wereequivalent. Tress D had some curl but less than that produced on A, B,or C. Tresses B and C had a slight oily appearance but no surface oilcould be detected. Tress D was "fluffier" and more natural in appearancethan B or C.

Tresses C and D where shampooed 2 times using a blank shampoo and thensubmitted to a subjective comb test. On a scale of 1 to 5 with 1 beingthe best and 5 being the worst tress C received a net rating of 2.75while tress D received a rating of 3.75.

EXAMPLE 2

This example shows the preparation of a novel polymeric compositionwhich was prepared in two parts and combined.

Part 1 consisted of 53.8 grams of a silanol endblocked fluid of theformula (VI) where all R⁴ are the methyl group and x has a value of 30to 40 and 52.8 grams of cyclic siloxane mixture of formula (VII) whereall R⁴ are the methyl group and z varied from 1 to 4. The two componentsof Part 1 were combined and mixed thoroughly. This mixture had aviscosity of 10.4 centistokes.

Part 2 consisted of 2.96 grams of chlorobenzylethyltrimethoxysilane,1.20 grams of tetrabutyl titanate and 54.3 grams of the cyclic siloxaneused in part 1. The three components or Part 2 were combined and mixedthoroughly.

Parts 1 and 2 were combined in air at room temperature. The finalproduct has a viscosity of 26.7 centistokes. A room temperature curedfilm produced a soft gel. A film cured at 150° C. for 1 hour produced asoft gel.

EXAMPLE 3

Two (E and F) 2 gram European Brown tresses of virgin human hair weremoistened with water, wound onto standard perming rods and treated with10 grams of an ammonium thioglycolate acid solution (pH=10). After 45minutes the hair was rinsed while still in the rods and blotted toremove excess moisture. The following procedures were accomplished foreach tress:

Tress E was saturated with a 2.2% aqueous solution of hydrogen peroxideand allowed to stand for 5 minutes.

Tress F was saturated with a 5% aqueous triethanolamine solution(pH=8-9) and held for 5 minutes. 10.4 grams of the polymer produced inexample 2 was diluted in 90.0 grams of cyclomethicone (Dow Corning 344Fluid). This dilute solution was applied to the reduced hair. The tresswas placed in a 40° C. oven for 6 minutes.

Upon completion of the oxidization step, both tresses were removed fromthe rods, thoroughly rinsed with water, and hung to air dry for at least24 hours. Tress F was observed to have a tight curl, tighter than thatproduced on tress E. Both tresses were shampooed using a blank shampoo.Tress F was observed to have a conditioned curl upon drying and the feelwas judged to be very good.

What is claimed is:
 1. A method of conditioning hair consistingessentially of(A) reducing the hair (B) neutralizing the hair byapplying a solution comprising 1 to 50 weight percent of a siliconecontaining material selected from the groups consisting of the formulas##STR7## and mixtures thereof to the hair; wherein R¹ is independentlyselected from alkylene groups containing 1 to 10 carbon atoms, arylenegroups containing 6 to 10 carbon atoms, and alkarylene groups containing6 to 15 carbon atoms; any of said groups optionally containing an etheroxygen with the aliphatic segments thereof; Y is selected from ahalobenzyl group and an epoxy group; R² is independently selected froman alkyl group containing 1 to 6 carbon atoms and an aryl groupcontaining 6 to 10 carbon atoms; R³ is independently selected from thegroup R² and the groups --O--R² and --R¹ --Y where R¹, R² and Y are asdefined above; and x has the value of 1 to
 5. 2. A method as claimed inclaim 1 wherein Y is the chlorobenzyl group.
 3. A method as claimed inclaim 1 wherein the siloxanes are of the general formula ##STR8## and atleast one R³ group is represented by --R¹ --Y and the remainder of saidR³ groups are selected from R².